Multidimensional assessments of impulsivity in women with bulimia nervosa, bipolar disorders, and comorbidity.

BACKGROUND

This study investigated the shared and distinct features of emotional dysregulation and impulsivity in women with bulimia nervosa (BN) and bipolar disorder (BD) as well as their relationship with comorbidity between the two conditions.

METHOD

This study included data from 115 women with BN and 76 women with BD, including 37 individuals with comorbid BN-BD, from a psychiatric outpatient clinic as well as 72 healthy female controls. All participants underwent a diagnostic interview and completed several self-administered assessments of mood and impulsivity. Statistical analyses were conducted to compare mood and impulsivity across the BN-only, BD-only, BN-BD comorbid, and control groups.

RESULTS

The disorder groups exhibited significantly higher levels of affective lability, attentional impulsivity, sensitivity to punishment, negative urgency, and both internally and externally directed impulsive behaviors compared with the control group. Comorbidity with BN-BD was further associated with increased severity in anger, attentional impulsivity, reward sensitivity (fun seeking), and externally directed impulsive behaviors relative to the BN-only group. Among these shared psychopathological features, negative urgency was significantly higher in the BN-only and BN-BD comorbid groups than in the BD-only group, indicating its unique relevance to binge eating. Attentional impulsivity was the only parameter that demonstrated significantly greater severity in the comorbidity group than in both the BN-only and BD-only groups. This finding implies that attentional impulsivity is associated with an elevated risk of externally directed impulsive behaviors in the BN-BD comorbid group relative to the BN-only group.

CONCLUSIONS

BN and BD share overlapping affect dysregulation and impulsivity profiles. Negative urgency and attentional impulsivity may make major contributions to binge eating and external impulsive behaviors, respectively, in individuals with comorbid BN-BD. Our findings highlight the importance of targeting emotion regulation skills as well as behavioral control of binge eating and associated impulsive behaviors when treating individuals with BN and BD comorbidity.